1. Field of the Invention
The present invention relates to firefighting equipment and, in particular, to firefighting vehicles utilizing a movable tower for supporting a spray nozzle.
2. Prior Art
In fighting grass or brush fires, it is desirable to utilize a firefighting vehicle having a tower which mounts a high pressure nozzle that can be aimed remotely from the top of the tower. By elevating the nozzle above the firefighting vehicle, a much greater area can be traversed by the water discharged from the nozzle then if the nozzle were to be hand-held near the ground. There are many known firefighting vehicles utilizing towers mounting nozzles which can be elevated from a substantially horizontal position, assumed when the vehicle is transported to the sight of the fire, to a substantially vertical position, during which the firefighting equipment supported by the tower is operated.
For example, in U.S. Pat. No. 645,470, a portable water tower is disclosed. This device comprises a wheeled platform which supports a pair of standards which rotatably mount a tower. The tower supports a rigid conduit terminating in an adjustable nozzle at its upper end. The upper section of the conduit is rotatable so that the nozzle can be swiveled to the left or right. The tower is connected to the standards which support it only by a pair of trunnions which must bear the entire weight of the tower.
Other examples of vehicles utilizing water towers are disclosed in U.S. Pat. Nos. 562,895; 527,460; and 1,835,132. The disclosures of these patents are similar in that, in each apparatus disclosed, the tower is mounted on a turntable which is rotatably mounted to a wheeled vehicle. A disadvantage of the use of a turntable with this type of vehicle is that a turntable adds weight and expense to the construction of the vehicle. In addition, firefighting vehicles utilizing turntables usually do not utilize rotatable conduits, so that the entire tower must be rotated by the turntable in order to direct the water discharged from the nozzle. This requires the expenditure of greater amounts of mechanical or manual energy.
Another example is shown in U.S. Pat. No. 517,320. This patent discloses a firefighting vehicle utilizing an aerial ladder which is mounted to a wheeled platform by hinges and can be elevated by a jack screw extending between the ladder and the platform. A hose is mounted on the ladder and includes a section of rigid conduit which terminates in a flexible nozzle connection. The section of rigid conduit can be swiveled with respect to the conduit upstream sections of the conduit in order to direct the nozzle. A disadvantage with this type of construction is that the ladder provides a small base of support which results in instability of the ladder structure. The ladder structure may rock with respect to the supporting platform while the supported conduit conducts water under high pressures, which lessens the accuracy of the nozzle and creates hazards to personnel operating the device.
When fighting brush and grass fires, it is also desirable to utilize a vehicle for transporting the water tower which is small, rugged, and maneuverable. None of the aforementioned patents discloses a vehicle for transporting a water tower which can operate in a rugged terrain. Indeed, in many of the aforementioned disclosures, the vehicle for transporting the water tower must be pulled by a second motorized vehicle. In addition, the aforementioned vehicles are not sufficiently self-contained to provide an adequate firefighting station in a remote area. For example, none of them disclose the use of stabilizing means for the platform supporting the tower, or illuminating means for providing illumination during poorly lit firefighting conditions where it is necessary to provide an adequate light level so that personnel can avoid dangerous structures and can attend to smoking or smoldering objects which themselves do not give off light.
Accordingly, there is a need for a firefighting vehicle having a tower which supports a conduit having a nozzle which can be remotely adjusted, the water tower providing a large, stable base for supporting the conduit when raised to a vertical position, a vehicle which can traverse and operate in a rugged terrain, and a firefighting vehicle which is essentially self-contained.